system.net.mail requires starttls

try setting enableSSL to true

SmtpServer.EnableSsl = true;

Select allOpen in new window

https://msdn.microsoft.com/en-us/library/system.net.mail.smtpclient.enablessl.aspx

nope here is a different version

    Private Sub test(Optional ByVal smtp As String = "smtp.gmail.com")
        Dim toAdd As String = " test@gmail.com"
        Dim fromAdd As String = "test@gmail.com"
        Dim pass As String = "pswd"
        Dim client As SmtpClient = New SmtpClient(smtp)
        Dim mail As New MailMessage
        mail.From = New MailAddress(fromAdd)
        mail.To.Add(toAdd)
        mail.Subject = "Test Zip File"
        mail.Body = "This Is just a test"
        client.Port = 465 '465 587  25
        client.Credentials = New System.Net.NetworkCredential(fromAdd, pass)
        client.EnableSsl = True
        MsgBox("here")
        '   client.Timeout = Int32.MaxValue
        Try
            client.Send(mail)

        Catch ex As SmtpException
            MsgBox(ex.Message)
        End Try
        MsgBox("done")
    End Sub

port 465 times out
port 25 gives a starttls error
port 587 give required secure connection

Your code looks fine, assuming you are using a valid email/user/pass in your actual code.

This google support article has more ideas for testing
https://support.google.com/mail/answer/78775?hl=en

The first is to confirm that you can log into the account you are using manually and so validate your credentials

Another good test is telnet to confirm that a connection can be made from your machine
eg telnet smtp.gmail.com 587

<network host="smtp.gmail.com" enableSsl="true" ... />

kind the like us if its works for u


http://weblogs.asp.net/scottgu/tip-trick-enabling-ssl-on-iis7-using-self-signed-certificates